(1) Field of the Invention
This present invention concerns a dose indicator, and a fluid-product dispensing device that includes such an indicator.
(2) Description of Related Art
In the area of fluid-product dispensing devices intended to dispense several doses, and in particular in the area of sprays, many systems have been developed that are intended to indicate the number of doses dispensed or the number of doses remaining to be.
Most of these systems have many disadvantages. Thus, they are generally designed with several toothed wheels forming gear trains whose number depends on the number of doses to be counted. As a consequence, these counters or indicators can become very complex and bulky, and therefore expensive to manufacture and to assemble. In addition, the indication is generally in the form of numbers which are often difficult for the user to read, in particular when the dispensing devices are intended to dispense a large number of doses, such as up to 200 doses for example. Likewise, not all the current counter or dose indicator systems can be used by people with sight problems, and in particular by blind people. Another major disadvantage is the fact that the existing counters generally require a procedure for the assembly of the dispensing device which is modified by the presence of the counter, and which therefore differs from the usual assembly procedure. This increases the complexity of the device, and consequently involves greater cost.
In addition, a very important safety requirement is to avoid any risk of under counting, that is not to count a total or partial dispensing of the product. In order to eliminate this risk, it is necessary that the actuation of the counter should be effected during the stroke of the dispensing member, in particular of the valve element or stem, which occurs before the beginning of product expulsion. The length of this initial stroke is generally very short, typically of the order of 1 to 1.5 mm, and the various dimensional tolerances of the device reduce the latter to a few tenths of millimeters. Such a short actuating stroke renders the actuation of the counter difficult, and can involve the use of complex mechanisms to guarantee functional counting.
Furthermore, some pumps or valves can be used to dispense doses of different volume, changing only the actuating stroke of the piston or of the valve element. It is then generally necessary to change the actuating means of the associated counters or indicators in order to adapt to the different strokes.
Document GB-1 317 315 describes a counter that includes means to compensate for the planned tolerances between the actuator of the counter and the body of the device housing said counter, these means being actuated after the first use of the device. This system is complex and not very reliable, since it actuates during the normal actuation of the device, and therefore more or less efficient according to the manner in which the user actuates the device.